Short Description
When attempting to barter with Piglins, the Piglins will pick up gold items (except nuggets, probably intended), and will examine these items. However, they will only give the player something for Gold Ingot(s).
How to Reproduce
Just throw any gold item, say a Gold Block or Gold Shovel, at a Piglin. They will not throw you an item back. They will throw you an item if you give them a Gold Ingot.
Works as intended: https://www.minecraft.net/en-us/article/minecraft-snapshot-20w07a
The block post mentions piglins getting distracted and admiring all gold items, but only ingots are supposed to be a currency to them